The present invention is directed to a sealing cap for a writing, drawing or painting instrument with an opening for inserting the instrument into an interior space closed at the opposite end from the opening. At least one axially continuous air channel extends at least partly along the sealing cap.
Such a cap is disclosed in the Great Britain Patent Publication No. 21 74 374 A.
The patent publication discloses a sealing cap with a plurality of axially extending channels on the outside of a shaft with the channels being open radially outwardly and in communication with the interior of the cap by perforations in an end of the cap. If such a cap is swallowed, for example by a child, sufficient air should be supplied along the outer channels to prevent asphyxiation and, accordingly, keep such a possibly endangered person alive until medical attention is available.
Since outer channels and radial perforations can become soiled and partially blocked relatively easily in the normal use of the sealing cap, the required passage of air is not always insured. Moreover, such channels, formed by grooves and ribs located on the outside of the cap, impair the visual or aesthetic appearance the sealing cap and of the entire writing instrument and, accordingly, limit considerably the design possibilities of the cap.
In other sealing caps, such as disclosed in the patent publications EP 0 204 252 A1, NO-PS 33 264 and JP-GN/AS 61-11016, axial and/or radial perforations and, in part, channels within one end or on the outside of the sealing caps are suggested for providing air passages and preventing compression or the formation of a vacuum when opening or closing the instrument.
Many writing, drawing or painting instruments frequently have a tip part only pressed into an instrument shaft and this tip part usually fits securely into a sealed zone of the cap shaft. Unfortunately, the tip part can be accidentally detached from the instrument, particularly in older instruments, so that the tip part may remain in the cap when the sealing cap is removed with the result that an axially continuous aeration passageway would not be available. Furthermore, the outlet openings of the air passageways can also be easily blocked in such instruments.